Deleting evap and pcv

[gpchris]

Hey im having some trouble deleting the pcv system and evap. First of all i know ill have to delete some codes from the pcm. But yeah basically all i need to do is remove all the components, cap off the vacuum lines and add breathers to the valve covers right?

Heres a vacuum diagram.



Also should i remove the vacuum line from the tb to the valve cover? Its actually pre TB vacuum.

[SappySE107]

bad idea. Evap is one thing, PCV is another. Adding filters will hurt power and economy. I know this because I have had a 3.4 DOHC with this done and upon correcting the PCV setup, it was noticable in both areas. I would love to add a vacuum pump to a 60V6 to see what that does but I know on the DOHC, a catch can type setup works wonders in keeping the oil out of the intake.

The reason you want vacuum going to the crank case is simple. The pistons create a lot of pressure, and this works against them. Having a vacuum source helps the rings seal as well.

Evap cannister purge is pure emissions and will do nothing beneficial once removed.

[Dave96z34]

Yeah there is no reason to get rid of the pcv system. The vac also makes it have less air resistance and gives you more power.

[jmgtp]

Catch can does help a lot. No more oil in my intake.

I thought a dry sump system was necessary if you wanted to use a vacuum pump on it?

[SappySE107]

nope, dry sump would be awesome but you can run a catch can and a vacuum pump on the stock setup.

[jmgtp]

We're straying off topic now but, when you say vacuum pump, do you mean the real deal ones:


or something like a brake vacuum pump from a diesel:


Either way, for a belt driven one, I don't see where it could go on a dohc unless you take out the a/c compressor. I wouldn't trust an electric one to last long enough to be worth it.

[SappySE107]

Either? Even an electric one like the J bodies had for their brake booster at some point in time (80s?). The belt driven one would be more regulated based on RPM but I have no experience with these. I need a car worth modding that runs:P

[jmgtp]

The top one is the really good kind, multiple vanes, and I think they pull a lot of vacuum even at low rpm - they cost hundreds though and I think are fairly large. The diesel kind I'm not sure, but they must be pulling at least 17"hg on a large brake booster for a truck - I've considered the diesel kind for my power brakes. I'm starting to think my booster might be leaking. When I stop the engine and get out there is always a 5 second or so hiss from that area and my power assist isn't so powerful.

I'd consider this mod if I could devise a way to mount/drive it.

[HayesPerformance]

MOROSO has awesome oil/air separator tanks, and breather tanks, BUT not cheap........

IF you drive your car in winter, when its real cold out, My catch can fills with condensation and goop very fast.

Its amazing what they Keep/ get out of you engine!!!

[jmgtp]

Hayes which line do you use your catch can on?

I had mine on the pcv line but still got oil in the intake. Switched it to the breather, aka valve cover, line and no more oil in the intake. This seems kinds weird since airflow should only be going into the valve cover since it is on the non vacuum side of the tb. Unless at wot when there is no vacuum it is pulling from both sides...?

[mfewtrail]

If you're looking to rig up something cheap, an air/oil separator could be made to work as an oil catchcan.

[geoffinbc]

I have seen oil separators like the ones use on compressors plumbed into the PCV system. Kept all the oil out of the intake.

[HayesPerformance]

There are lots of cheap crapy ones on ebay for sale that will work IF you modify them and seal them properly. otherwise they don't hold vacuum well, and don't seperate oil/air very well at all....

There is a German made universal made one sometimes on ebay that works very well, easy to clean, empty, etc. but is NOT CHEAP, it was like $180 us

You could get a MOROSO one cheaper and still top quality....

[HayesPerformance]

A person has to be careful when using the air/oil seperators for compressors, you have to make sure you get one that CAN withstand higher tempertures, otherwise they are short lived....

lol, the bowl will disform and melt....

[tijuana_no]

i saw a pic of a catch can , but was hard to see how it was plumb up.
any of you have good pics of what you have done and good instructions on how to do it right.